class GrandFather1(object):
    pass


class Father1(GrandFather1):
    pass


class GrandFather2(object):
    pass


class Father2(GrandFather2):
    pass


class Son(Father1, Father2):
    pass


print(Son.__mro__)
# (<class '__main__.Son'>
# <class '__main__.Father1'>, <class '__main__.GrandFather1'>
# <class '__main__.Father2'>, <class '__main__.GrandFather2'>
# <class 'object'>)
